Ink jet printers are known and provide a number of advantages in the printing process. For example, ink jet printers are capable of providing relatively high-density color output at an acceptable printing speed. Furthermore, such printers are relatively inexpensive. As a result, it is desirable to utilize such printers in the formation of identification cards.
Identification card substrates generally have polyvinyl chloride (PVC) or polyvinyl chloride/polyvinyl acetate (PVC/PVCAc) surfaces. These surfaces can be printed using a Dye Diffusion Thermal Transfer (DDTT) technology where dyes and/or resins are deposited at or near the surfaces of the card substrates. Images printed on the surfaces of these card substrates are susceptible to defacement due to abrasion, exposure, water and other environmental conditions. Accordingly, a protective material should be applied over the printed card surface to protect the printed image.
To provide protection to the printed image on the card substrate surface, overlays can be applied to the printed card surface. Thin film overlays can be used to provide edge-to-edge protection to a printed surface. Unfortunately, such thin overlays only provide limited protection to the printed card surface.
In the alternative, patch laminates can be applied to printed card surfaces to provide additional protection to DDTT images. Patches generally made of a polyester (PET) film and a thermal adhesive provide a bond between the polyester film and the card surface. Although patch laminates exhibit resilient protection for a printed card surface, patch laminates do not generally provide edge-to-edge protection to the printed card surface since they are formed slightly smaller than the card. Additionally, after lamination of a patch, card substrates can become warped along the outer edges of the identification card.
Ink-receptive films have been applied to card substrates to form an ink-receptive surface thereon. FIG. 1 illustrates an ink-receptive film 10 formed of a clear or an opaque backing layer (e.g. PET, PVC, etc.) 12, on which an ink-receptive coating 14 is applied in accordance with the prior art. A layer of adhesive 16 is generally applied between the backing layer 12 and a surface 18 of a rigid or semi-rigid card member 20. Card member 20 is a conventional blank card substrate that is typically formed of PVC or suitable material. Ink receptive film 10 is laminated to card member 20 through application of heat and pressure. Portions of ink-receptive film 10 that overhang the edges of card member 20 are then trimmed as necessary. A laminate layer 22 can be laminated to a bottom surface 24 of card member 20 by adhesive layer 26 in an effort to counterbalance stresses that are applied to card member 20 as a result of the lamination of backing layer 12 of ink-receptive film 10 to surface 18 of card member 20.
Unfortunately, the above-described process of forming an ink-receptive card substrate using an ink-receptive film is problematic. The layers of adhesive, ink-receptive film, card member, and the laminate, result in a complex and expensive ink-receptive card substrate. Also, the backing layer of the ink-receptive film can potentially delaminate from the card member due to its exposed edges, thereby limiting the useful life span of the ink-receptive card substrate. Additionally, the image that is printed to the ink-receptive surface that is formed by the ink-receptive coating of the film can be defaced due to abrasion, exposure, water and other environmental conditions. As a result, images that are printed to ink-receptive surfaces of card substrates or printed directly to card surfaces should be protected by a protective material that provides both edge-to-edge protection as well as resiliency.